1. Field of the Invention
The present invention relates generally to a hybrid touch screen device for an electronic device, and a method of operating thereof. More particularly, the present invention is related to improving accuracy in data entry of a hybrid touch screen device including a hybrid touch panel using different touch modes.
2. Description of the Related Art
In general, there are various kinds of electronic devices that include input units for data input and output units for data output. A typical example of such an input unit may be a key button unit, and a typical example of the output unit may be a display unit including a liquid crystal display (LCD) module.
More recently, a touch screen device have been developed that can perform data input/output (I/O) and display data at the same position in order to considerably reduce the size of an electronic device and diversify functions thereof. In such a touch screen device, a transparent touch panel is disposed on an LCD module to perform input and output simultaneously. Touch panels are generally classified into various types based on their physical construction/mode of operation, for example, a resistive touch panel, a capacitive touch panel, an ultrasonic touch panel, an optical (infrared) sensor touch panel, and an electromagnetic induction touch panel.
In general, a touch screen device inputs accepts data input by using a user's finger or a stylus. The conventional stylus merely provides a thinner way to touch items on the screen in lieu of a finger. However, recently, a hybrid touch screen device has been developed that includes a pen-shaped input unit (generally referred to as a touch pen) as an auxiliary data input unit and a user can selectively input data by such a touch pen. The touch screen device includes a touch panel and a separate sensing unit, and separately uses data input by the touch pen and data input by the touch panel.
When a touch pen is used separately from a data input mode of a touch panel as described above, the typical mode of operation is by electromagnetic induction. In other words, a pen touch panel in which a plurality of coils are disposed perpendicular to each other (generally referred to as a digitizer panel) is included in an electronic device as a sensing unit for the touch pen that is separate from a touch panel, and a resonance circuit is included in a touch pen. An alternating current (AC) signal is applied to a coil of a sensing pad for operation. When a touch pen is adjacent to a display panel of such an electronic device, a coil of a pen touch panel adjacent to the touch pen forms a magnetic field. In resonance with the magnetic field, a resonance frequency is generated by the touch pen. The resonance frequency is detected by a control unit of the electronic device, so that a relevant touch position can be determined.
Furthermore, in addition to detecting and displaying only a touch position of a touch pen, for example, the thickness of handwriting can be represented according to a pen pressure at which a user presses the touch pen against a display panel of an electronic device. Accordingly, a feeling of actually using a pen is given to the user, thus increasing the use convenience.
On the other hand, an electric device having a hybrid touch screen device generally uses a capacitive touch panel to detect a user's finger, and generally uses an electromagnetic induction pen touch panel to detect an input of a touch pen. Thus, there are two recognition systems required for the hybrid touch screen device to be operable.
However, in the above-described hybrid touch screen device, data may be accidentally or unintentionally inputted in situations that are not intended by the user. For example, when the user touches a portion of his or her palm to the touch screen device of the electronic device (what is referred to as a “palm touch”) while holding the touch pen in order to use a touch pen function, not the pen touch panel but the main touch panel configured for detection of a finger detects the palm touch, so that data input is randomly detected. This is an input error from the viewpoint of the user, and also degrades product reliability, as the device cannot determine an accidental touch, such as a palm touch, from a purposeful touch.